Thanks to those who kindly tested the last version of LockRattler on their Macs with T2 chips, it transpires that my test to determine whether a T2 chip is present was a dismal failure.

It has been widely reported that trying to run the EFI firmware checker tool eficheck on a Mac equipped with a T2 chip fails. However, instead of those Macs not having eficheck installed, it is present in the normal location, just broken. That appears a strange choice by Apple, but it means that looking for eficheck is no way of determining whether a Mac has a T2 chip.

Instead, the only correct way at present appears to be to use system_profiler to report on the iBridge present, using the command
system_profiler SPiBridgeDataType

Even that doesn’t return the results which you might expect, though. Systems which don’t have a T1 or T2 chip still return a ‘correct’ result, and those with T1 chips report the results for that ‘iBridge’ instead. So the correct test is to search for the presence of T2 in the result from that call.

Except that even that isn’t guaranteed to be robust: the result can also include a firmware version and serial number which could (however improbably) contain the two consecutive characters T2. Therefore, this new version of LockRattler bases its decision on the occurrence of ' T2 ', with leading and trailing spaces, as the most specific test.

This new version, which should at last work without error on T1- and T2-equipped Macs, is now available from here: lockrattler415
and from Downloads above.

As before, please report any issues in comments below.